1. Field of the Invention
The invention relates to a coupling device to be arranged between an output shaft of an electric motor and an input shaft of a reducing gear for driving a screen or a leaf that is part of closing, solar protection or projection equipment. The invention also relates to home automation equipment comprising, inter alia, such a coupling device.
According to the present invention, a screen comprises a movable part consisting of a sliding panel or a set of strips which is moved, generally by rolling, between a raised position, wherein it leaves an opening clear, and a lowered position, wherein it shuts off said opening. Such a screen may be a rolling shutter or door. The screen may also be a blind for solar protection, for example a terrace blind or a Venetian blind. A screen may also be a screen used for image projection, notably in video format. According to the invention, a leaf is a part of closing device, such as a door leaf of a gate or a shutter hinged about a vertical axis on the edge of a window.
2. Brief Discussion of the Related Art
The use of an electric motor associated with a reducing gear for driving the rolling shaft of the flexible sliding panel of a rolling shutter or blind is known. These devices are frequently integrated within a so-called tubular actuator which is inserted inside a rolling tube and which is rigidly connected thereto by means of a wheel. The coupling between the output shaft of the motor and the input shaft of the reducing gear is sometimes difficult since each of these devices is equipped with bearings supporting the respective shafts thereof, which are not necessarily aligned or even parallel. This gives rise to noise from running the actuator, and premature wear of the reducing gear, at least in some configurations.
One solution incorporating a universal joint on one of the shafts may be envisaged. However, it is relatively expensive and complex to implement, while only allowing misalignment of the axes of the shafts to be coupled to a limited extent.
Moreover, U.S. Pat. No. 2,011,147 discloses the use of an assembly of mutually movable parts, for rotatably securing coupling elements each provided with a hub and a broadened cross-section. The three-part assembly comprises two lateral parts each interacting with a coupling element and a central part. The manufacture of this device is complex and costly. Moreover, the transmission of the torque between a coupling element and an associated lateral part is based on the engagement of ribs in grooves, with merely axial relative movement capability. The parts of the three-part assembly and the coupling elements are complex and thus need to be produced with precision and assembled with care, which increases the cost of the system according to the prior art.
Similar problems are encountered with the device known from FR-A-970 629.